Hypersensitivity to any component of this medication.
Severe renal disease.
Patients with severe renal disease will accumulate aminosalicylic acid and its acetyl metabolite but will continue to acetylate, thus leading exclusively to the inactive acetylated form; deacetylation, if any, is not significant.
The half life of free aminosalicylic acid in renal disease is 30.8 minutes in comparison to 26.4 minutes in normal volunteers, but the half life of the inactive metabolite is 309 minutes in uremic patients in comparison to 51 minutes in normal volunteers. Although aminosalicylic acid passes dialysis membranes, the frequency of dialysis usually is not comparable to the half-life of 50 minutes for the free acid. Patients with end stage renal disease should not receive aminosalicylic acid.